Trump tweeted: “Mike Pompeo, Director of the CIA, will become our new Secretary of State. He will do a fantastic job! Thank you to Rex Tillerson for his service! Gina Haspel will become the new Director of the CIA, and the first woman so chosen. Congratulations to all!”

The former ExxonMobil CEO is only the latest in a long line of departed White House leaders, but he is arguably the most prominent to date. For context, a collection of Fortune coverage below.

Finally, one from the Fortune archives: Brian O’Keefe’s 2012 magazine story on ExxonMobil’s big bet on shale gas. “With his silver hair, dark suits, and deep Texas drawl, Tillerson is the very picture of a big oil executive,” O’Keefe writes. “In person, he comes across as relaxed and extremely comfortable in his own skin. Until, that is, the subject of environmental concerns and the media coverage of the shale gas boom comes up. Then suddenly his temper flashes. ‘I think we have to deal in facts,’ he says, his voice rising.”